Concrete block forming machine



Jan. 12, 1943. H. A. WELLNITZ 2,308,132

CONCRETE BLOCK -FORMING MACHINE Filed Jan. 16, 1942 3 Sheets-Sheet l Jan. 12, 1943. H. A. WELLNITZ 2,308,132

CONCRETE BLOCK-FORMING MACHINE Filed Jan. 16, 1942 5 Sheets-Sheet 2 F 'IG. 2.

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57 swam 0v HARRYAJWELLNITZ v (I;

i 3% a W Patented Jan. 12, 1943 UNITED STATES PATENT OFFICE This invention relates to machines for producing molded products of plasticmaterials, such as concrete building blocks, wall tiles and other analogous products.

In concrete block-forming machines, particularly machines of the type utilizing a sliding mix transferring and measuring drawer, wherein the drawer is movable between positions of registration with a mix-containing hopper and a spaced mold box and wherein a drop platen is used for effecting final compaction of the mix received within the mold box, some difilculty has been encountered in the matter of causing such a machine to produce formed cementitious blocks of uniform and standard height dimensions. It is obvious that if such blocks vary in height, even though but slightly, difficulties ensue when the blocks are placed in superposed wall-forming courses, since builders base their plans on structures in which the blocks are each assumed to possess a definite height dimension.

Accordingly, it is an object of the present invention to provide improved means in a machine of the character indicated which, when operated at production speeds, will form successive blocks with each block possessing a standard height dimension, avoiding the lack of uniformity in this regard hitherto present.

It is another object of the invention to provide a concrete block-forming machine wherein a switch mechanism is automatically operated by the drop-type platen when the desired degree of compaction of the concrete mix in the mold box is obtained, the switch serving to actuate mechanism by means of which the platen is elevated and the formed block moved to a position adapted for its discharge or removal from the machine. 1

Another object of the invention is to improve the design and arrangement of a block-forming machine of the type set forth in order to enhance its accuracy in operation, convenience in control and general efliciency.

A further object is to provide such anarrangement of parts and method of operation as will produce an improved product.

Further and other objects and advantages will be hereinafter set forth in the accompanying specification and claims, and shown in the draw.- I

In the drawings: Fig. 1 is a vertical sectional view taken through a block-forming machine formed in accordance with the present invention;

Fig. 2 is a vertical sectional view on the line 11-11 of Fig. 1, showing the mold box, drop platen and vibrating mechanisms;

Fig. 3 is a detail elevational view of the. rock shaft operating mechanism;

Fig. 4 is a detail side elevational view, showing the sliding mix drawer, the platen frame and the trip mechanism for causing the platen to drop;

Fig. 5 is a diagrammatic view of the drive motor circuits and their control switches;

Fig. 6 is a detail horizontal sectional view taken on the plane indicated by the line VI--VI of Fig. 4;

Fig. 7 is a detail sectional view on the line VII-VII 0! Fig. 6;

Fig. 8 is a detail vertical sectional view taken through a cam operated switch mechanism disposed in one of the electrical circuits employed to control the operation of the machine.

Referring to the drawings, the numeral l0 designates the stationary base frame of the cementitious block-molding machine forming the present invention. The frame includes a stepped bottom wall Ii, upstanding vertical side walls II, a vertical front wall l3 and a horizontally disposed top wall It.

Slidably mounted for movement in a confined horizontal and linear path on the top wall I is a mix-receiving and transferring drawer IS, the latter being open at the top and bottom. When this drawer is normally positioned, as in Fig. 1, the sameis disposed below and in registration with a stationary mix-containing hopper ii. The cementitious mix gravitates from the hopper into the drawer l5, filling the latter with a measured quantity of the mix, the quantity being sufficient to effect the formation of a single block. The drawer I5 is also formed with a horizontally disposed closure shelf l1, which, when the drawer is advanced to its mix-discharging position in registration with a mold box l8, serves to close the bottom of the hopper I6 and thereby prevent loss or spilling of the mix from the outlet of th hopper.

If desired, the mold box may be provided with rotary agitators I9, which are adapted to be driven by amotor 20, suspended from the under side of the shelf II. These agitators may operate after the manner set forth in my co-pending application, Serial No. 266,584 filed April '1, 1939, now Patent No. 2,270,829, dated January 20, 1942.

The mold box l8 comprises an open topped rectangular frame, which is stationarily posi tioned in recesses tir'formedinthe uhber. e

tions of these springs are received within suitable retaining sockets provided in connection with the base frame It, the springs 25 serving to produce a resilient supporting medium for the mold box in order to facilitate its vibration. The upper edge portions of the mold box terminate normally approximately evenly with the upper surface of the top wall l4 of the base frame. so that the messuring drawer may be advanced thereover and into exact vertical registration therewith. The

thereof a removable pallet 25 on which a cement block is adapted to'be formed, the pallet being removable from the mold box after the formation of the block and provides a base for facilitating the handling of the block. When placed in the mold box, the pallet rests on the perforated bottom wall 22 thereof so that the perforations in the wall 22 will be closed or covered.

The drawer I is slidably operated at timed intervals by means of an electric drive motor shown at 21. This motor through suitable speed reducing mechanism drives a main control shaft 23, the latter being suitably journaled in bearings provided in connection with the base frame I 0. The shaft 28, at one-end, (see Fig. 3) has fixed thereto a disk 29, the latter being provided with a multiplicity of spaced circularly arranged apertures 30. Secured to the outer face of the disk by means of bolts 3| passing through the apertures 30 is a tangentially extending rock shaft operating arm 32. Similarly secured to the inner face of the disk 29 is a second rock shaft operating arm 33, which is spaced laterally from the arm outer end of a second crank arm 43 fixed to the shaft 35. This engagement causes the rock shaft to be partially revolved in a direction opposed to that imparted thereto by the operation of the arm 32, and by this means, the drawer I 5 is re- 5 stored to its normal position in registration with the hopper I3.

The c ration of the drive motor 21 is controlled by the ployment of circuits and ancillary devices disclosed diagrammatically in Fig. 5. In this go figure of the drawings, the drive motor has been mold box is adapted to receive at the bottom indicated as being of the three-phase type. The three main conductors are disclosed at 44, 45 and 43. To the conductor 44, there is connected a lead 41 from which extends a conductor 48 which 5 leads to a manually operated starting switch 49.

Also included in the conductor 43 is a cut-out or emergency stop switch 50 of a manually operated type. Extending from the conductor 43 on the opposite side of the switch 50 as regards the switch 49 is a lead H which extends to the field winding 52 of a solenoid or relay switch 53. From the other side of the winding 52, a lead 54 extends to a conductor 55 which is joined as at 53 to the return conductor 46. Thus. by depressing the switch 49 and closing the circuit therethrough,

the field winding 52 will be excited to actuate the armature 58a of the switch 53, bringing the contact disks 51, 58 and 59 thereof into engagement with the normally spaced sets of contacts 60,3!

and 52 which are respectively joined with the motor leads 41, 55 and 63 and united with the main conductors 44. and 45.

This comprises the initial starting circuit and results in the operation of the motor 21 and the 32. A third arm 34 is also secured to the outer 45 main shaft 23. Fixed to the shaft 28 is a pluface of the disk 29 by means of bolts passing through the apertures 30, the arms 32, 33 and 34 while being carried by the disk 29 are disposed in different vertical operating planes.

A multiplicity of apertures 30 are utilized for the purpose of providing for adjustment in the operating positions of said arms. Journaled in bearings provided in the side walls of the base frame It is a rock shaft shown at 35. This shaft has fixed thereto one or more drawer-operating arms 36. To the upper end of each of these arms. there is connected, as at 31, one end of a link 38, which is disposed at the side of the drawer Hi. the other or forward end of the link being pivoted as at 39 to said drawer, so that upon the oscillation of the rock shaft 35. sliding motion will be imparted to the mix transfer drawer.

As shown in Fig. 3, when the main shaft 23 is rotated, the tangential arm 32 will first engage with a roller 40 mounted on the outer end of a crank arm 4| fixed to the rock shaft 35. One edge of the arm 32 has wiping engagement with the roller 40, which engagement is sufiicient to rock the shaft 35 in a direction causing the advance of the drawer I5 from its material receivin position in registration with the hopper It to its material discharging position in registration with the mold box It. When this movement has been effected, the arm 32 is rotated sufficiently to be removed from engagement with the roller 40,

rality of switch operating cams, the first of which is shown at 64. This cam is formed with an extended peri heral portion 65 which terminates in shoulders 93, forming an inset peripheral portion 61. Engaging with the perimeter of the cam 94,

as in Fig. 1, is a roller 58 provided on the outer end of an arm 39 which is pivoted as at I0 to the base It. The central portion of this arm is pivotally connected with the lower end of a link II,

the upper end of the link, as in Fig. 8, having seated engagement with the pivoted snap action lever I2 of a timing switch I3. With the lever I2. there is connected a coil spring 14 which is adapted to impart sharp off-center movement to the lever I2.

It will be seen that when the main shaft 23 is initially rotated by the manual actuation of the switch 49, one of the shoulders 55 of the cam will effect the elevation of the arm 59, the link II and the switch lever I2, causing the contact head -of a shunt lead I9 to one of a pair of contacts 30 found in a switch 8| which corresponds in construction and operation to the switch I3. From the contact 80, a wire 82 extends to one of a pair of spaced stationary contacts 83 of the relay switch 53, which pair of contacts is bridged, when the winding 52 is excited, by a disk 84, the latter being mounted on the armature 58 and spaced from the disk 51. Current then passes through the disk 84 and thence by way of a lead 85 to the conductor 49, passing through the emergency switch 50, lead field winding 52 of the relay switch, lead 54 and conductor 55 to the trunk conductor 48. By this means, the drive motor 21 is maintained in operation and the switch 49 may be released, since the motor circuit is kept closed by the engagement of the raised portion 85 of the cam 84 with the roller of the arm 89.

The raised peripheral portion 55 of the cam 84 is usually slightly in excess of 180 degrees of the cam periphery and is suiliciently prolonged so that the motor 21 is operated to advance the drawer I5 from its position in registration with the hopper I9 to its position in registration with the mold box I8, allowing for the contents of the drawer to be discharged into the mold box and to .then provide for the restoration of the drawer to its normal position in registration with the hopper IS. The roller 59 then engages with the depressed peripheral portion of thecam 54, causing the switch 13 to open and thereby discontinue the operation of the motor 21.

Also, fixed to the shaft 28 is a second timing cam 88, the peripheral portion of which is depressed as at 8'1 and extended as at 88 for engagement with the actuating arm of a vibrator switch 89. Immediately after the closing of the switch 18 by the action of the cam 64, the cam 88 operates to close the switch 89, causing current to flow from the lead 11, conductor 18 through the spaced contacts 90 of the switch 89 by the engagement of the head 9| of the switch 89 with the contacts 90, and thence by way of the lead 92 to the vibrator motor 93. The return side of the vibrator motor is joined by a conductor 94 with a the trunk conductor 45.

The vibrator motor 99, as shown in Figs. 1 and 2-, is mounted in the lower part of thebase I0 of the machine and is utilized to drive a rotatable shaft 95 journaled in bearings provided in brackets 95 in which the lower ends of the coil springs 25 are mounted. The shaft 95 is equipped with an eccentric 91, so that when the shaft 95 is rotated, vibratory motion is imparted thereto and thence to the mold box, causing the settling of the cementitious mix in the mold box to produce a block of required density. This vibration is comprises a horizontally disposed plate having its under surface ribbed as at 99 to conform to the configuration of the upper part of the mold box and its core members 23. The outer ends of the platen project through vertical slots provided in ayOke-shaped supporting frame I00. Also, the platen at its ends may be provided with rollers IM to control its vertical sliding movement. Normally, the platen is maintained in an elevated position by providing the same centrally as at I03 for engagement with a spring-pressed slidably mounted rod I04. The outer end of this rod is formed with an eye which receives a finger I05 projecting laterally from a vertically jour- I naled trip bracket I08. The lower end of this bracket is pmvided with a longitudinally extending arm I01 having an inwardly directed outer end I08 which is slotted as at I09. Pivotally mounted in this slot as at I I0 is a stud II I carrying a horizontally positioned roller I42 at its lower end.

This roller is disposed in registration with a wedge element II3 projecting laterally from the side of the drawer I5. Due to its peculiar pivotal mounting in the outer end of the arm I01, the roller II2 upon forward movement of the drawer toward the mold box merely swings idly about the horizontal pivot IIO, so, that the position of the arm I01 is not disturbed. However, upon rearward or retracting movement of the drawer I5, the inclined surface of the wedge element II3 engages the roller H2, and since the stud III- is, by the formation of the slot I09, prevented from swinging about the axis of the pivot I III, the consequence is that the wedge surface of the element H3 forces the roller II2 outwardly and laterally, swinging the arm I01 about its vertical axis and imparting similar movement to the finger I05, which moves the rod I04 and releases said rod from engagement with the shoulder I03 of the platen. Such release allows the platen to fall by its own weight on the mass of cementi- I tious material contained in the mold box, pressing the material down and more firmly compacting the same.

In order to assure the formation of a block having an exact height dimension, the vibration of the mold box is continued while the platen is in which is received the threaded end of a verwith an upstanding boss I02, which is shouldered ticaliy disposed rod H5. The upper end of this rod carries a fixed horizontal bar H6, and in the outer end of this bar there is mounted an adjustable switch actuating screw II1. When the platen first drops on the cementitious mix in the mold box, the lower end of the screw I I1 is spaced from the head I I8 of the switch I I4. However, as the vibration of the,mold continues and the platen slowly settles, the lower end of the screw II1 will, at a desired time, engage with the head II8 to close the switch II4. With the switch II4 closed, see Fig. 5, current passes from the conductor 44, lead 41, conductor 48, lead 11, and conductor 18 to the first of a pair of spaced contacts II9 of the switch H4. The current then passes through the head II8, second contact II9, conductor 48, lead 5|, field winding 52 of the relay switch 53, lead 54 and conductor 55 to the return trunk conductor 48. The energizing of the field 52 closes the relay switch 53, starting the motor 21 and rotating the shaft 28.

Fixed on the shaft 28 is a third cam I20, having raised peripheral portion I2I and a depressed peripheral portion I22. The raised portion I2I of the cam 22 in relation to the corresponding raised portion 55 of the cam 54 has been indicated in Figs. 1 and 5. This relationship is such that after the switch I3 has been opened, following return of the drawer I5 to its normal position, the motor 21 is stopped. However, the raised portion I2I of the cam I22 then contacts with the operating arm of the switch 8i in order that the head I28 of the switch 8| will be brouglit into contact with the spaced pair of contacts 80 and a circuit through the switch 8| thereby made possible.

This circuit is not immediately established but only takes place when the switch II4 has been closed by the descent of the platen to a predetermined position. It will be understood that the shaft 28 does not rotate unless the motor 21 is in operation. Therefore, the operating arm of the switch 8| remains in a dwell position until the switch H4 is closed. The motor 21 is then energized, as above explained, and the shaft 28 revolved. With the operating arm of the switch 8| engaged with the raised portion I2I of the cam I20, current will flow by way of the lead 41, conductor 48, lead 11, conductor I8 to the contacts 80, passing through the head I23, thence through the wire 82 to the disk 84, lead 85, cutout switch 50, lead 5|, winding 52, lead 54 and conductor 55 to the return trunk conductor 48.

With the switch 8| so closed and the shaft 28 rotating by the operation of the 'motor 21, the third arm 34 carried by the disk 29 contacts with a pin or roller carried on the outer end of a crank I24 fixed to a second rock shaft I25, which is journaled in the frame of the machine below the rock shaft 35. The rock shaft I25 carries lifting cams I26, which engage with the central portion of a plurality of lift levers I21. These levers are pivoted as at I28 to the frame of the machine and their forward or free ends engage with the under surface of a vertically movable lift bar I29. This bar carries a plurality of upstanding pins I30 which, upon the elevation of the bar, are adapted to pass through the perforations provided therefor in the bottom wall 22 of the mold box, so that the upper ends of the pins may engage with the pallets 25 to effect the elevation of said pallets and the formed blocks carried thereby. Also, the outer ends of the bar I28 carry upstanding posts I3I which, before the pins I30 engage with the pallet 25, contact the lower ends of registering depending posts I82 carried by the platen 98. Due to the wiping engagement of the arm 34 with the crank I24, the rock shaft I25 is revolved sufllciently to cause the elevation of the bar I29, the pallet 25 and the formed cementitious block positioned thereon to a plane above that of the mold box, facilitating the removal of the formed block from the machine. Simultaneously therewith, the platen is elevated until it is again fastened in its elevated position through engagement of its shoulder I08 with the spring-pressed rod I04. At this stage, the raised portion of the cam I2! is rotated beyond the actuating end of the lever for the switch 8|, causing the latter switch to open and discontinuing the operation of the motor 21, finishing the complete working cycle of the machine.

The present invention thus provides a drop platen and sliding drawer type of block-forming machine having a high productive capacity, one substantially automatic in operation (except for the manual actuation of the starting switch 48 for each cycle of machine operation) and most trolled by the movement of the platen, and the degree of compaction of the block, to regulate the height dimension of the finished block. I prefer to make the cams 54 and I20 separate members in order that their operating positions on the shaft 28 may be relatively varied to obtain adjustment in the periodic operations performed thereby.

The machine is essentially simple in its constructional features, rugged in design and capa: ble of sustained use in the commercial production of concrete blocks and the like.

While I have described a preferred form of my improved machine, nevertheless it will be under-' stood that the same is subject to considerable variation without departing from the scope of the following claims.

What I claim is:

1. In a machine for molding cementitious building blocks, a frame, a mix-containing hop per, a mix-receiving drawer slidably mounted on the frame, a stationary mold box, an electric motor and its actuating circuit, a shaft driven by said motor, means actuated by the rotation of said shaft for moving said drawer between its mix-receiving position in registration with said hopper and a mix-discharging position in registration with said hopper and a mix-discharging position in registration with said mold box, cir- I cult-controlling means for said motor actuated by said shaft for interrupting rotation of the latter when said drawer returns to its mix-receiving position, a horizontally extending vertically moving drop platen slidably carried by said frame, latch means for maintaining said platen in an elevated inactive position during the sliding movement of the drawer, a trip actuated by the return movement of said drawer to its mixreceiving position to release said latch means whereby to cause the platen to drop into forcible engagement with a cementitious block-forming mix positioned in the mold box, a switch for said circuit adapted to be automatically actuated upon predetermined compaction of the mix in the mold box through movement of the platen,

- the actuation of said switch serving to eflect reespecially the provision of automatic means, consumed rotation of said shaft, means actuated by said shaft upon its resumed rotation to elevate the formed cementitious block from the mold box, and circuit-controlling means for arresting the rotation of said shaft following the elevation of the formed block.

2. In a machine for molding cementitious building blocks, a mold, means for filling said mold with a cementitious mix, a vertically movable drop platen, an electric motor for operating said mold filling means and said platen, an operating circuit for said motor, and a controller for said circuit operative automatically upon compaction of the mix to a predetermined height dimension within said mold to actuate said circuit, whereby to removethe weight of said platen from engagement with the mix in said mold.

3. In a machine of the class described, an open-topped mold, means for filling said mold with a cementitious block-forming mix, a drop platen movable into compressive engagement with the mix body contained within said mold and with the full weight of the platen sustained by and pressing on said body, and means automatically responsive upon compaction of the mix within said mold to a predetermined height dimension to remove said platen from saidcompressive engagement with said body.

4. The structure defined in claim 8, in combination with means for vibrating the mold and the cementitious mix contained therein while the drop platen is pressing on the mix.

5. A building block-forming machine of the type having a mold, means for'supplying a cementitious mixture to the mold, means for simultaneously applying pressure to .the mixture in mold and vibrating the latter to compact the mixture therein, means for ejecting the formed blocks after compaction, and power driven means for operating the machine; comprising means for interrupting the action of said power driven means during the pressure applying and vibrating operations and means for automatically resuming the action of said power driven means after the block being formed has been compacted to a predetermined height dimension.

6. A machine for molding cementitious building blocks, comprising a frame, a mold supported stationarily by said frame, a drawer slidably supported by said frame for movement between a receiving position in which a. cementitious mix is introduced therein and a discharge po sition in which the drawer is disposed above said mold to release its contents into the latter, an electric drive motor, a primary operating circuit for said motor, a manually operated switch for closing said circuit and energizing said motor, automatic means actuated by the motor when the latter is energized for moving said drawer between its mix-receiving and mix-discharging positions and restoring the drawer to its mix-receiving position, a drop platen mounted in said frame for vertical movement and nor-= mally disposed above said mold, latch devices for maintaining said platen in an elevated and active position above said mold, means operative automatically upon return movement of said drawer from its mix-discharging to its mix-receiving position to trip said latch devices and thereby cause gravitational descent of said platen into direct contact with the mix contained in said mold, means for vibrating the mold to cause settling of the mix contained therein, including an electric motor and its operating circuit for effecting automatic actuation of said vibrating means while said mix transfer drawer is in registration with said mold and following retraction of said drawer and while the platen is in contact with the mix contained in the mold, means operated by said drive motor for elevating a formed cementitious block from said mold and lifting said platen into reengagement with said latch devices, a second operating circuit for said driving motor, a switch forming a part 01' said second operating circuit, and means carried by said platen and engageable with said last-named switch to close automatically said second circuit upon predetermined compaction oi the block- Iorming materials in said mold.

'7. A machine for producing molded building blocks of cementltious composition comprising a mold box, a drawer movable into and out of registration with said box to deliver to the latter a moldable cementitious mix, a drive motor, a shaft driven by said motor, means actuated by said shaft for controlling the movement or said drawer between mix-receiving and mixdischarging positions, a primary operating circuit for said drive motor including a manually closeable switch for initiating the operation of said motor, automatic switch means operated by said shaft for deenergizing said circuit following the return of said drawer to its mix-receiving position and the delivery of its contents to said mold, means for vibrating the mold and its contents including an electrical actuating motor and' its operating circuit, automatic switch means operated by said shaft for closing the operating circuit of the motor for operating said vibrating means in order to cause vibration of the mold and its contents when the drawer occupies its retracted mix-receiving position, a vertically movable drop platen arranged above said mold a box, latch means normally maintaining said platen in its elevated position above said mold box, means operative automatically upon the movement or" the drawer from its position of registration with said mold box to its mix-receiving position to trip said latch means and thereby cause said platen to fall into direct contact with the body of the mix undergoing vibration in said mold box, means operated by said drive motor for elevating a formed cementitious block from said mold box and lifting said platen into reengagement with said latch means, a second operating circuit for said drive motor, a switch forming a part of said second circuit and disposed adjacent to said platen, and means carried by said platen and engageable with said last-named switch to close automatically said second circuit upon predetermined compaction of the mix in said mold, whereby to effect automatically the operation of said block elevating means and the restoration of said platen into elevated holding engagement with said latch means.

8. A machine for producing molded building blocks of cementitious composition, comprising a mold, means for filling said mold with a cementitious mix, a vertically movable drop platen adapted to engage and compress the mix con-' tained within said mold, means for vibrating the mix when the latter is subjected to the weight of said platen, an automatic switch means controlled by the degree of compaction of said mix through the joint action of said platen, and vibrating means for removing the platen from engagement with said mix and terminating the operation of said vibrating means.

HARRY A. WEILNITZ. 

